San Diego State University is located at the border between, USA and Mexico on Kumeyaay land in a diversity hotspot. Our lab studies serves these communities by studying species with binational distribution that have ecological and cultural value. We study how the Anthropocene is impacting these plants.
Students from the 2021-2022 cohort in the Binational Studies Program
We have a collaborative project supported by NSF- Bridging Ecology and Evolution project with Drs. Seema Sheth (North Carolina State University), Chris Muir (U of Hawaiʻi), Jeff Diez (U of Oregon), and Jay Sexton (UC Merced). We will bridge evolutionary approaches with population ecology models by investigating whether evolution can rescue populations of scarlet monkeyflowers from decline when they encounter rapid environmental change. We will address the following goals about how the probability of evolutionary rescue varies across a species’ range:
Quantify natural selection in contrasting environments by linking traits, fitness components, and population growth,
Assess the extent to which the breeder’s equation predicts realized rates of trait evolution across the species’ range, and
Determine where in the species’ range evolutionary rescue is most likely based on standing genetic variation for fitness.
To address these objectives, we will perform a resurrection study comparing ancestors and descendants derived from seed collected before and after a period of severe drought and heat in western North America. We will transplant seedlings from leading-edge, central, and trailing-edge populations of the perennial herb, Erythranthe cardinalis, into three common gardens at differing range positions and quantify natural selection on traits, additive genetic variances for traits and fitness, and differences in population growth rates and traits between ancestors and descendants.
Reticulate evolution by hybridization is considered a common process shaping the evolution of many plant species, however, reticulation could also be due to incomplete lineage sorting in biodiverse systems.
We study reticulate evolution in a variety of plant groups such as Pinus, Eucalyptus, Arbutus, etc. using a variety of approaches such as genetics/genomics, morphology, phenology, physiology and ecology.
Evolution of reproductive systems
We are interested in understanding the evolution of reproductive systems in plants and their ecological consequences. The presence of cosexual and unisexual individuals in sympatry allowed us to test evolutionary hypotheses to sexual separation such as inbreeding depression and sexual allocation and to explore the consequences of sexual separation on herbivory patterns.
We also study the bisexuality which has been proposed to be an innovation of angiosperms but the development of bisporangiate cones in Pinus allowed us to show that mechanisms for producing bisexual structures predates the angiosperm – gymnosperm split and also has provided insights of the ancestral state of angiosperms.
Bisporangiate strobilus (also called bisexual cone) of Pinus johannis at the time of pollination.
We study how climate change disrupts reproduction, for example pollen viability and phenology, testing the hypothesis that lower elevation populations, experiencing higher temperatures will be more adapted to heat stress, differences that will be reflected at the vegetative and reproductive level, providing the genetic material to higher elevation populations to allow them to cope with climate change.
We study the flower development in dioecious species, the cellular and genetic mechanisms that remodels hermaphroditic flowers into unisexual.
Abnormal development of anthers of female flowers of Opuntia spp.
The Transnational Approaches to Sustainable Food Futures: Integrated High-Impact Learning Experiences and Pathways to Food Careers project is supported by the USDA-NIFA HSI program.
It is run in collaboration with Drs. Pascale Joassart-Marcelli, Ramona Perez, Changqi Liu, John Love, Stephen Welter from SDSU and Waverly Ray from Mesa College. It is part of the projects supporting the Center for Better Food Futures.
We are offering scholarship to support students joining our program. More information can be found here.
Our lab is involved training students on the how to use edible native plants and sustainable practices to preserve our biodiversity hotspot.
This project is linked to the new multidisciplinary course CAL-400.